A site manager claims it was common knowledge in the Canberra construction industry that subcontractors needed to pay a “standover” man to avoid trouble from the union.

Donald McInnes was a site manager at Victory Homes in the ACT in 2013 when he witnessed the "intimidation and bullying tactics" of the CFMEU, the Royal Commission into Trade Union Corruption has heard.

He told the hearing in Canberra on Tuesday that three members of the union, including ACT secretary Dean Hall and Halafihi `Fihi' Kivalu, trespassed on the worksite on numerous occasions.

On one occasion, Mr McInnes alleged he was assaulted by Mr Kivalu after asking the official to sign in before entering the site. In his witness statement to the commission, Mr McInnes said the union used "standover tactics" to try to intimidate the business because it would not sign an enterprise bargaining agreement.

He knew of two subcontractors, including plasterer Jian Yu He, who had been forced to make cash payments to Mr Kivalu - who the union says it no longer employs.

"It was common knowledge in the ACT construction industry that Fihi would take cash payments from subcontractors in exchange for their workers to work on commercial sites without hindrance from the CFMEU," Mr McInnes said in his witness statement.

Mr He earlier told the hearing he was forced to pay Mr Kivalu $5000.

"Fihi said to me, if this money is not paid, then he will cause trouble," Mr He said.

He wrote a cheque for more than $2000 to the union a month ago after being told he needed to get 10 people to sign up as members, the commission heard.

Mr McInnes said Mr Hall, Mr Kivalu and another man entered the Victory Homes site without permission in 2013 and called workers off the job amid safety concerns.

When Mr Kivalu turned up the following day, Mr McInnes said the official became agitated when asked to sign in to visit the site.
The men argued and Mr Kivalu pushed Mr McInnes out of the way, causing him to lose his balance, the builder said.

He also outlined another occasion when Mr Hall trespassed on the site despite being asked to wait for Fair Work Building Commission representatives to attend, telling Mr McInnes: "you and your Fair Work mates can get f****d".

The CFMEU has distanced itself from its former employee Mr Kivalu, saying the allegations should be investigated by police.